Moving a coin or token from Layer 2 to Layer 1 can take anywhere from a few minutes to a few hours. An average time in ‘normal’ conditions would be between 30 minutes and 3 hours – but it could be longer at certain times.
It all depends on how active the respective Layer 2 rollup is during that general time. Somewhat counterintuitively, more activity means the withdrawal will be processed sooner. This is because rollups work by batching many transactions occurring on the rollup (L2) and processing them in one bundle with the output being recorded on L1. A rollup prefers to fit as much activity in one “batch” as possible, as it is more economical for the rollup operator. This is analogous to how an airplane would prefer to fly a full plane rather than a mostly empty one – it is spending the fuel; it wants to move as many people or goods as possible!